CB650M-BX Mother Board
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6. Real-Time Clock, CMOS RAM, and Battery
The real-time clock is compatible with DS1287 and MC146818 components.
The clock provides a time-of-day clock and a multi-century calendar with
alarm features and century ro l l o v e r. The real-time clock supports 256 bytes of
battery-backed CMOS SRAM in two banks that are reserved for BIOS use.
A coin-cell battery powers the real-time clock and CMOS memory. When the
computer is plugged into a wall socket, the battery has an estimated life of
t h ree years. When the computer is plugged in, the 3.3V standby current fro m
the power supply extends the life of the battery. The clock is accurate to +1 3
minutes/year at 25˚C with 3.3V Stand-by voltage applied.
7. I/O Controller
The IT8671F controller from ITE is an ISA Plug and Play-compatible,
multifunctional I/O device that provides following feature s :
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Two serial ports
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One parallel port with ECP and EPP support
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Interface for one 1.2MB, 1.44MB, and 2.88MB diskette drive
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PS/2 style mouse and keyboard interfaces
The BIOS Setup program provides configuration options for the I/O
c o n t ro l l e r.
7-1. Serial Port s
The motherboard has two 9-pin D-sub serial connectors located on the back
panel. The serial ports support NS16C550-compatible UARTs and can be
assigned as COM1(3F8), COM2(2F8), COM3(3E8), or COM4(2E8).
7-2. Parallel Port s
The connector for the multimode bidirectional parallel port is a 25-pin D-Sub
connector located on the back panel.
CB650M-BX(1,2¿Â) 00.5.12 2:8 PM
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